(PureBasic) HTTP - Verify Server is a Trusted Root CA

Demonstrates how to only allow connections to an HTTP server having a certificate with a root that is in our list of trusted CA root certificates.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkTrustedRoots.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkGlobal.pb"

Procedure ChilkatExample()

    ; Starting in v9.5.0.49, all Chilkat classes can be unlocked at once at the beginning of a program
    ; by calling UnlockBundle.  It requires a Bundle unlock code.
    chilkatGlob.i = CkGlobal::ckCreate()
    If chilkatGlob.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkGlobal::ckUnlockBundle(chilkatGlob,"Anything for 30-day trial.")
    If success <> 1
        Debug CkGlobal::ckLastErrorText(chilkatGlob)
        CkGlobal::ckDispose(chilkatGlob)
        ProcedureReturn
    EndIf

    ;  On my particular system, the root CA cert for this URL is not pre-installed.
    ;  Note: This may be different for you.
    ;  Also, this example was written on 29-May-2015.  This URL was valid at the time,
    ;  but may not be valid at a future date.
    url.s = "https://animals.nationalgeographic.com/animals/invertebrates/starfish/"

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  Require that the SSL/TLS server certificate is not expired,
    ;  and that the certificate signature is valid.
    ;  This does not ensure that it has a chain of authentication to
    ;  a trusted root.  To ensure that, the TrustedRoots object (below) is required.
    CkHttp::setCkRequireSslCertVerify(http, 1)

    ;  Do the HTTPS page fetch (through the SSH tunnel)
    html.s = CkHttp::ckQuickGetStr(http,url)
    If CkHttp::ckLastMethodSuccess(http) <> 1
        Debug CkHttp::ckLastErrorText(http)
        CkGlobal::ckDispose(chilkatGlob)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    Debug "The HTTP GET was successful."

    ;  Now let's require that HTTP requests to SSL/TLS servers that don't have trusted CA roots
    ;  should fail.
    trustedRoots.i = CkTrustedRoots::ckCreate()
    If trustedRoots.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  Indicate that we will trust any pre-installed certificates on this system.
    ;  (The meaning of pre-installed certificates depends on the operating system, and in
    ;  some environments there is no such thing as pre-installed certificates.  See the reference
    ;  documentation for the TrustedRoots class.)
    CkTrustedRoots::setCkTrustSystemCaRoots(trustedRoots, 1)

    ;  Activate the trusted roots globally for all Chilkat objects.
    ;  This call really shouldn't fail, so we're not checking the return value.
    success = CkTrustedRoots::ckActivate(trustedRoots)

    ;  Given that our previous HTTP GET likely kept the connection open,
    ;  make sure that all HTTP connections are closed before re-trying.
    ;  Otherwise, we'll simply be re-using the pre-existing connection.
    success = CkHttp::ckCloseAllConnections(http)

    ;  Now let's try fetching the URL again.  It should fail this time because
    ;  there is a requirement that the SSL/TLS server certificate must have a trusted root,
    ;  and the trusted root for this URL is not installed on my system (but may be different for you..)
    html = CkHttp::ckQuickGetStr(http,url)
    If CkHttp::ckLastMethodSuccess(http) <> 1
        Debug CkHttp::ckLastErrorText(http)
        Debug "Good, the HTTP request failed as expected."
    Else
        Debug CkHttp::ckLastErrorText(http)
        Debug "Hmmm... we did not fail as expected?"
    EndIf



    CkGlobal::ckDispose(chilkatGlob)
    CkHttp::ckDispose(http)
    CkTrustedRoots::ckDispose(trustedRoots)


    ProcedureReturn
EndProcedure